Modular lathes



P. D. GEORGE Oct. 24, 1967 MODULAR LATHES 3 Sheets-Sheet 1 OriginalFiled May 15, 1964 INVENTOR PETER D. GEORGE ATTORN EYS 1967 P. D. GEORGE3,348,438

MODULAR LATHES Original Filed May 15, 1964 5 Sheets-Sheet 2 FIG. 2

INVENTOR Fl G. 3 PETERDGEORGE ItI ....q @615 ATTDRNEYS P. D. GEORGE3,348,438

MODULAR LATHES Oct. 24, 1967 3 Sheets-Sheet 5 Original Filed May 15,1964 FIG.4

NW W m5 m D mR W t. b-OAE ATTORNEYS United States Patent 3,348,438MODULAR LATHES Peter D. George, 156 Crabtree Road, Quincy, Mass. 02169Original application May 15, 1964, Ser. No. 367,720. Divided and thisapplication Jan. 23, 1967, Ser. No.

1 Claim. (Cl. 82-23) ABSTRACT OF THE DISCLOSURE A lead screw engagingmechanism is provided for selectively connecting and disconnecting acarriage to lead screw. The mechanism includes a pair of half-nutsnormally urged apart and out of engagement with the lead screw. A pairof articulated links are eccentrically mounted to a control shaft and tothe half-nuts whereby rotation of the control shaft will bring the nutsinto engagement with the lead screw. A pivot latch is provided forlocking the shaft and the nuts in driving engagement with the leadscrew.

This application is a division of my US. application Ser. No. 367,720,filed May 5, 1964, and now abandoned.

This invention relates generally to lathe machinery and moreparticularly is directed towards a lathe base support and driving headin cooperation with a variety of interchangeable modules adapted toperform selected machining operations. This invention is also directedtowards improvements in lathe components.

A lathe generically defines a machine adapted to remove metal from aworkpiece by gripping it securely in a clamping device and rotating itunder power against a suitable cutting tool. Lathes are able to performa number of machining operations such as facing, boring and threading,and, depending upon the design of the machine, these operations may becarried out under manual, semi-automatic or completely automaticcontrol. While machines of this type generally are quite versatile as aclass, a specific lathe unit is relatively restricted as to its range ofoperations. For this reason, machine shops normally require severalindividual lathe machines, each adapted to perform certain machiningoperations for which each machine is particularly designed. Since eachmachine is a relatively expensive piece of equipment, a sizable capitaloutlay is required to properly outfit a machine shop.

Accordingly, it is a general object of the present invention to provideimprovements in lathe machines.

Another object of this invention is to provide a basic lathe unitadapted to accommodate a variety of interchangeable modules forperformin a variety of different machining operations.

Still another object of this invention is to provide a lathe machinewhich is readily convertible from one mode of operation to another.

A still further object of this invention is to provide a lathe machinewith cooperating modules which may function on a manual, semi-automaticor completely automatic basis.

More particularly, this invention features a lathe comprising a basicdriving head and cylindrical ways of hardened metal on which areselectively mounted interchangeable modules each adapted to perform oneor more selected operations such as threading, boring, or the like.Certain ones of the modules may be programmed to cycle automatically andperform selected predetermined operations on a completely automaticbasis. Other modules may be employed for semi-automatic operation whilefurther modules may be operated manually for use in producing individualparts not suitable for automatic production.

But these and other features of the invention, along with furtherobjects and advantages thereof, will become more fully apparent from thefollowing detailed description of a preferred embodiment of theinvention, with reference being made to the accompanying drawings inwhich:

FIG. 1 is a view in perspective of a precision lathe module set up on alathe base,

FIG. 2 is a fragmentary side elevation of a lead screw engagingmechanism employed in the precision lathe of FIG. 1,

FIG. 3 is a fragmentary end elevation partly broken away of the FIG. 2device,

FIG. 4 is a fragmentary side elevation partly in section showing detailsof the screw engaging mechanism of FIG. 2,

FIG. 5 is a side elevation showing further details of the lead screwmechanism of FIG. 2 and,

FIG. 6 is a cross-sectional view taken along the line 66 of FIG. 3.

Referring now to FIG. 1, there is illustrated a precision lathe using abase support and cylindrical hardened ways. Dilferent modules have beenadded to the basic unit to provide a lathe adapted to perform theconventional cutting as well as threading. The assembly includes acarriage 96 adapted to be move back and forth along ways 20 and 22 bymeans of a hand wheel 98 which rotates a pinion (not shown) which inturn meshes with a rack 100 extending parallel between the ways 20 and22. Mounted on top of the carriage 96 for transverse movement is a slide102. The slide carries a holder 104 for selected cutting tools. Crossfeed of the slide 102 is controlled by a hand wheel 106 which operates aworm in mesh with the slide 102.

A tail stock assembly 108 is supported by ways 110 mounted to the motorhousing and to an arm 112. The arm 112 also carries a screw selector 114which controls the speed of a lead screw 116. The lead screw is adaptedto drivingly engage the carriage 96 by means of the engaging mechanismillustrated in FIGS. 2 through 6.

This lead screw engaging mechanism includes a frame 118 fixed to thecarriage 96. Mounted within the frame 118 is a pair of half-nuts 120'and 122 disposed to either side of the lead screw and normally urgedapart by means of a spring 124 compressed between lugs 126 and 128extending from the sides of the half-nuts. The half-nuts 120 and 122which are adapted to move to and away from one another within the frame118 are also connected to articulated links 130 and 132 eccentricallyconnected to a stub shaft 134 extending through the frame 118 at rightangles to the lead screw 116. The stub shaft may be manually rotatedthrough a limited arc. It will be understood that by pulling the arm 36forwardly as viewed in FIG. 3, the stub shaft will be rotated and thelinks 130 and 132 will pull the half-nuts towards one another againstthe force of the spring 124 so as to engage the half-nuts with the leadscrew. The lead screw being engaged to the carriage 96 of FIG. 1 willcause the carriage to be advanced at a speed determined by the speed ofthe lead screw.

The half-nuts may be locked in a lead screw engaging position by meansof an arm 138 and latch 140 best shown in FIGS. 2 and 3. The latch 146is pivoted about a pin 142 and formed with a shoulder 144 adapted toengage a shoulder 146 formed in a collar 148 integral with the stubshaft 144. It will be understood that when the arm 136 is biased toengage the half-nuts, the latch will drop to engage the shoulder of thestub shaft and thus lock it. The half-nuts may be released by merelylifting the arm 138 to disengage the latch from the shoulder 146.

3 While the invention has been described with particular reference tothe illustrated embodiments, it will be understood that numerousmodifications thereto will appear to those skilled in the art. Also, itwill be understood that the above description and accompanying drawingsshould be taken as illustrative of the invention and not in a limitingsense.

Having thus described the invention, what I claim and desire to obtainby Letters Patent of the United States is: A driving mechanism for lathemodules and the like, comprising (a) a lead screw, (b) means forrotating said lead screw, (c) a support fixed to said module andextending into proximity with said lead screw, ((1) a pair of half-nutsmounted to said support and disposed on opposite sides of said leadscrew, (e) spring means normally urging said half-nuts apart and out ofengagement with said lead screw, (f) a shaft rotatably mounted to saidsupport and perpendicular to said lead screw, (g) a lever arm mounted tosaid shaft,

(h) a pair of links each connected at one end eccentrically to saidshaft and at the other end to said half-nuts and adapted to pull saidhalf-nuts into driving engagement with said lead screw upon rotation ofsaid arm,

(i) locking means mounted on said support for locking said half-nuts inan engaged position,

(3') said locking means including a shoulder formed on said shaft and alatch pivoted to said support about an axis parallel to said shaft andadapted to engage said shoulder when said half-nuts are in an engagedposition, and,

(k) another lever arm mounted to said latch for moving said latch intoand out of shoulder engaging position.

References Cited UNITED STATES PATENTS LEONIDAS VLACHOS, PrimaryExaminer.

